HOW DOES HIV SPREAD DURING SEX?

To spread HIV during sex, HIV virus particles in blood or sexual fluids must be transmitted from one person to another. Body fluids that can carry and transmit HIV during sex include semen, vaginal fluid, and blood. HIV can be transmitted when infected fluid gets into someone’s body.

Safer sex guidelines are ways to reduce the risk of spreading HIV during sexual activity.

UNSAFE ACTIVITIES

Unprotected sex has a high risk of spreading HIV. The greatest risk is when body fluids touch the soft, moist areas (mucous membranes) inside the rectum, vagina, or at the tip of the penis. These can be damaged easily, which gives HIV a way to get into the body. The receptive partner is more likely to get HIV, although HIV might be able to enter the penis, especially if it has contact with HIV-infected blood or vaginal fluids for a long time or if it has any open sores.

Some people think that they can’t transmit HIV if they pull their penis out before they reach orgasm. This isn’t true, because HIV can be in the fluid that comes out of the penis before orgasm (pre-seminal fluid).

To be safe, assume that your sex partners have HIV. You can’t tell if people are infected by how they look. They could be lying if they tell you they do not have HIV, especially if they want to have sex with you. Some people got HIV from their steady partners who were unfaithful just once.

Even people who got a negative test result recently might have HIV. They might have gotten HIV after they got tested, or they might have gotten the test too soon after they were exposed to HIV. Read more about HIV testing.

CHOOSE SEXUAL ACTIVITIES WITH LITTLE TO NO RISK

    • Choose sex that is less risky than anal or vaginal sex. There is little to no risk of getting HIV through oral sex.
    • You can’t get HIV from sexual activities that don’t involve contact with body fluids (such as kissing, massage, and self or mutual masturbation).
    • Be aware of your and your partner’s bodies. Cuts, sores, or bleeding gums increase the risk of spreading HIV. Rough physical activity also increases the risk.
    • Oral sex has low risk of transmitting HIV but is possible if sexual fluids get in the mouth and if there are bleeding gums or sores in the mouth. Condoms or dental dams can be used as barriers during oral sex. Condoms without lubricants are best for oral sex because most lubricants taste awful.

USE CONDOMS THE RIGHT WAY EVERY TIME YOU HAVE SEX

    • Condoms are highly effective in preventing HIV and other sexually transmitted infections (STIs), such as gonorrhea and chlamydia.
    • Use water-based or silicone-based lubricants to help prevent condoms from breaking or slipping during sex. Oil-based lubricants like Vaseline, oils, or creams can damage condoms and other latex barriers. Be sure to use water-based or silicone-based lubricants.
    • Learn the right way to use an external condom (sometimes called a male condom) and an internal condom (sometimes called a female condom).

TAKE PREP

    • PrEP (pre-exposure prophylaxis) is medicine people at risk for HIV take to prevent HIV.
    • If taken as prescribed, PrEP is highly effective for preventing HIV from sex.
    • PrEP is much less effective when it is not taken as prescribed.

DON’T HAVE SEX WHEN YOU’RE DRUNK OR HIGH ON DRUGS

    • You’re more likely to engage in risky sexual behaviors.
    • If you do have sex, use condoms the right way every time.

DECIDE NOT TO HAVE SEX

    • Not having sex (abstinence) is a 100% effective way to make sure you won’t get HIV through sex.
    • You can be abstinent at different times in your life for different reasons that may change over time.
    • Not having sex also prevents other STIs and pregnancy.

GET TESTED AND TREATED FOR OTHER STIS

    • If you have another STI, you are more likely to get HIV. Getting tested and treated for other STIs can lower your chances of getting HIV.
    • Many people with an STI may not know they have it because they don’t have symptoms.
    • Find a testing site near you.

IF YOUR PARTNER HAS HIV, ENCOURAGE THEM TO GET AND STAY ON ANTIRETROVIRAL TREATMENT

 WHAT IF YOU AND YOUR SEXUAL PARTNERS ALREADY HAVE HIV?

Some people with HIV don’t see the need to follow safer sex guidelines when they have sex with other people who also have HIV. However, it still makes sense to follow the above guidelines. If you don’t, you could be exposed to other STIs such as herpes simplex virus (HSV), human papillomavirus (HPV), hepatitis, or syphilis. If you have HIV, these diseases can be more serious.

Also, though uncommon, you might get re-infected with a different strain of HIV. When a person with HIV gets another type, or strain, of the virus it is called HIV superinfection. The new strain of HIV can replace the original strain or remain along with the original strain. Superinfection may cause some people to get sicker faster because the new strain of the virus is resistant to the ART regimen they’re taking to treat the original strain. However, hard-to-treat superinfection is rare. Taking antiretroviral medications (ARVs) to treat HIV can help protect you from getting a superinfection. If you and your partner(s) have HIV and keep an undetectable viral load, there is effectively no risk of transmitting HIV to others through sex. In addition, following the above guidelines for safer sex will reduce the risk.

SET YOUR LIMITS

Decide how much risk you are willing to take. Know how much protection you want to use during different kinds of sexual activities. Before you have sex,

    • Think about safer sex.
    • Set your limits.
    • Obtain water-based lubricants, condoms, and other barriers, and be sure they are easy to find when you need them.
    • Talk to your partners so they know your limits.

Stick to your limits. Don’t let alcohol, drugs, or an attractive partner
make you forget to protect yourself.

WHAT SHOULD I DO IF I HAVE HAD UNSAFE SEX?

If you think you have had sex with someone who has HIV (or any other bloodborne virus) make sure you get tested as soon as possible.

If you want to continue being sexually active, use a condom until you get your test results. If you have HIV but don’t yet know it, and you don’t use a condom, you may pass on HIV to another person.

You may also be able to get post-exposure prophylaxis (PEP). Taken within 72 hours of possible exposure, PEP can stop HIV from spreading in your body. However, it is not available everywhere. Your healthcare provider will be able to talk you through your options.

THE BOTTOM LINE

HIV infection can occur during sexual activity. Sex is safe only if there is no HIV, no blood or sexual fluids, or no way for HIV to get into the body.

You can reduce the risk of infection if you avoid unsafe activities or if you use barriers like condoms. Decide on your limits and stick to them.

Reviewed June 2024

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